Testers capable of testing multiple device types and voltage or current ratings are known in the art, but do not place the tested device under load conditions simulating actual use of the device. Testers capable of testing a single device type of a single voltage or current rating under a load are known, but are not capable of testing multiple device types or devices of varying voltage or current ratings with a single tester. The present invention overcomes the limitation in the devices and methods known in the prior art and allows a single tester to be used to test multiple types of devices and devices of various voltage or current ratings under a load similar to typical operating conditions.